Joan Rivers Hospitalized After Cardiac Arrest

Joan Rivers was rushed to a New York City hospital in critical condition today after an emergency call that she was in cardiac arrest, according to a law enforcement source.

"This morning, Joan Rivers was taken to The Mount Sinai Hospital in New York, where she is being attended to," Sid Dinsay, a spokesman for The Mount Sinai Hospital, said in a written statement. "Her family wants to thank everybody for their outpouring of love and support. We will provide an update on her condition as it becomes available."

The New York City Fire Department transported a woman matching Rivers' description to Mt. Sinai Hospital after receiving a call that the woman was in cardiac arrest at an Upper East Side clinic, Yorkville Endoscopy, an FDNY source said. The law enforcement source confirmed the woman was Rivers.

TMZ reported that Rivers was having surgery on her vocal chords at the clinic.

Rivers, 81, had been hard at work of late, co-hosting her E! TV show, "Fashion Police" and doing stand-up comedy. According to Ticketmaster, she had seven shows planned across the U.S. for November.

"Ignore aging: Comedy is the one place it doesn’t matter. It matters in singing because the voice goes. It matters certainly in acting because you’re no longer the sexpot. But in comedy, if you can tell a joke, they will gather around your deathbed," she wrote in the Hollywood Reporter in 2012. "If you’re funny, you’re funny. Isn’t that wonderful?"

Get real-time updates as this story unfolds. To start, just "star" this story in ABC News' phone app. Download ABC News for iPhone here or ABC News for Android here. To be notified about our live weekend digital reports, tap here.